Apparatus for feeding paper webs and the like, for the production of cardboard tubes

ABSTRACT

Apparatus for feeding paper webs and the like, for producing cardboard tubes, characterized in that it comprises a plan modular structure ( 1 ) with a development mostly longitudinal and exhibiting two opposite surfaces ( 1   a   , 1   b ), one ( 1   a ) of the surfaces supporting pairs of shafts or axes ( 2, 2 ′) horizontally oriented parallel to the one surface and located at a preset distance from the ground, each of the shafts or axes ( 2, 2 ′) intended to support at least a reel ( 3, 3 ′) from which a paper web unwinds, so that the output webs run parallel and superimposed to each other along the other surface ( 1   b ) of the structure, and in that it comprises automatic means, associated with the structure ( 1 ), for the cutting and mutual gluing of the webs which unwind from two different reels ( 3, 3 ′) of a same pair of shafts ( 2, 2 ′).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a United States National Phase application ofInternational Application PCT/IT2003/000459 and claims the benefit ofpriority under 35 U.S.C. § 119 of FI2002A000181 filed Sep. 26, 2002, theentire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains to an apparatus for feeding paper websand the like for the production of cardboard tubes.

BACKGROUND OF THE INVENTION

A technique commonly adopted for the production of cardboard tubes isone making use of tube-forming machines provided with a spindle on whichthere are wound—to form a series of spirals being superimposed andoffset of a predetermined pitch—a plurality of webs of paper or similarmaterial suitably glued in correspondence of a surface intended toresult in facing relationship to the spindle. The gluing is not operatedon the first web of the series, as it is intended to directly makecontact with the spindle. The motion of the webs is ensured by a beltwound around the spindle which, in addition, causes the rotation and theadvancement of the tube under formation with respect to the spindle'slongitudinal axis.

A tube-forming machine so constructed and operating is described in WO95/10400 and WO 95/10399.

The webs, being spirally superimposed and mutually glued to form thetube, unwind from corresponding feeding reels.

Each of the reels is mounted on a corresponding support associated withmeans for gluing the respective web. A plurality of supports,independent from each other, are mounted in such a way as to form intheir entirety a kind of fan-like figure, so that each web is directedtowards the spindle of the tube-forming machine according to acorresponding angle of incidence. In relation to this, the devicespresently known for supplying webs to tube-forming machines arerelatively bulky, take up excessive space and force the webs to runalong cross routes and in different planes, thereby contributing to apoorly rational exploitation of the available spaces at the productionsite.

SUMMARY OF THE INVENTION

The main object of the present invention is to overcome the abovedrawbacks.

The present invention makes it possible to exploit the available spacesand reduce the overall cost of the plant. Besides, it allows making anauxiliary structure which facilitates the handling and fixing of thereels onto the respective support axes.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic view in perspective of an apparatus according tothe invention;

FIG. 2 is a front view of an apparatus according to the invention;

FIG. 3 is a rear view of the apparatus of FIG. 2;

FIG. 4 is a plan view of the apparatus shown in FIGS. 2 and 3; and

FIG. 5 shows schematically the combination of an apparatus according tothe invention with a tube-forming machine (T);

FIG. 6 is a schematic view of an automatic device for cuting and gluingthe webs;

FIG. 7 is another schematic view of the automatic device for cutting andgluing the webs;

FIG. 8 is another schematic view of the automatic device for cutting andgluing the webs;

FIG. 9 is another schematic view of the automatic device for cutting andgluing the webs; and

FIG. 10 is a front view of a device for controlling the tension of thewebs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in particular, FIG. 1 is an apparatusaccording to the invention comprising a plan structure (1) having adevelopment mostly longitudinal and which exhibits two opposite surfaces(1 a, 1 b). In correspondence of the first surface (1 a), the structure(1) supports pairs of rotating shafts or axes (2, 2′) horizontallyoriented parallel to the same surface (1 a).

Each of the shafts (2, 2′) is intended to support a corresponding reel(3, 3′) from which a web (N1, N2, N3; N1′, N2′, N3′) of paper materialor the like can unwind to supply a tube-making machine (T).

Because of the disposition of the axes for supporting the reels (3, 3′),these result parallel to each other, disposed vertically and orientedorthogonal to surface (1 a) of structure (1). The axes (2, 2′) of eachpair of reels (3, 3′) are coaxial and independent from each other, sothat the rotation of a shaft (2, 2′)—that is, of a reel (3, 3′)—does notimply automatically the rotation of the other shaft (2, 2′) of thepair—that is, of the other reel (3′, 3).

The tube-forming machine (T) may be of a type known to those skilled inthe art and, therefore, will not be described in further details.

The structure (1) is provided, in correspondence of its lower base, witha plurality of slits or windows (10) through which the webs unwindingfrom reels (3, 3′) can pass from the side of the first surface (10) tothe side of the second surface (1 b).

On the side of the second structure (1 b), the structure (1) supports aplurality of rollers (4) for guiding and tensioning the webs (N1, N2,N3) fed to the tube-forming machine (T).

In correspondence of the terminal side of structure 1 that is, on theexit side of webs fed to the tube-forming machine, the structure (1) hasa plurality of tanks (5) holding liquid glue to be used for gluing theventral (facing downwards) part of all the webs, with the exception ofthe one intended to make direct contact with the spindle of thetube-forming machine. In practice, if “n” indicates the number of webs,the number of tanks (5) will be “n−1”.

The webs to be glued transit above the tanks (5), in correspondence ofwhich there are provided suitable rollers and gluing means (50). Therollers are associated with relevant actuators (51) engaged with thesurface (1 a) of structure (1) and by means of which the webs (N2; N3)can be moved close to or away from the respective glue-feeding means.The web intended to make direct contact with the spindle of thetube-forming machine being indicated by (N1).

FIG. 3 shows a reservoir (52) and a pump (53) for feeding glue to thetank (5). This web-gluing system is known per se to those skilled in theart.

As illustrated in FIGS. 2 and 4, the webs moving towards thetube-forming machine run parallel and superimposed along the secondsurface (1 b) of the structure (1) and up to the tubeforming machine(without engaging fan-like trajectories as it occurs, instead, with theconventional devices), which allows exploiting more effectively theavailable spaces and orienting the structure more conveniently withrespect to the tube-forming machine.

Moreover, the shape of the structure (1) allows utilizing an auxiliarystructure (6) mounted on that side in correspondence of which there areprovided the shafts (2, 2′) for reels (3, 3′) and comprising ahorizontal crosspiece (60) mounted, at a preset level from the ground,onto more supports (61) and intended to act as a guide/support for amotor-driven elevator (62) which, in turn, is mounted for sliding on thesame crosspiece (61). The elevator (62) can be suitably used (operatedby a remote control not shown in the drawings but known per se) to liftthe reels (3, 3′) from the ground and keeping them suspended upon thepositioning thereof on axes (2, 2′). Associated with the structure (1)are automatic means for unreeling the webs without interrupting therelevant flow toward the tube-forming machine (T) when one of the reels(3, 3′) runs out of paper material.

Shown in the illustrative diagrams of FIGS. 2, 5, 6, 7, 8 and is anautomatic device for cutting and gluing the webs in a manner so-called“in full flight”, which actually allows feeding the webs with continuitywithout interrupting the flow thereof toward the tube-forming machine(T) when one of the two reels of each module runs out of paper material.Such apparatus, being provided on each module of the structure, that is,for each pair of reels (3, 3′) comprises, located under two web-guidingrollers (4), an operating unit with a presser cylinder (7) orthogonallyoriented to the direction in which the webs unwind, a blade (8)associated with a relevant actuator (80) for cutting the webs andlocated above the presser cylinder (7) and, intermediate between thepresser cylinder (7) and the actuator (80) of blade (8), a flexiblelamina (9) intended to maintain the head of the other web adherent upona fixed guiding surface (90). When one reel (for example, the reel ofweb N1) is about to run out of material (which is sensed by acorresponding photocell located close to the same reel at a presetdistance from the relevant axis 2 and supported by a fixed part of thestructure), the presser (7) is automatically operated after apredetermined time. An operator will have glued beforehand a piece ofboth-sides-adhesive tape (91) on the head of a stand-by web (N1′), sothat the actuation of the presser (7) causes the gluing of the reelingoff web (N1) on the adhesive tape attached on the head of the stand-byweb (N1′). In this regard, it should be noted that both webs (N1, N1′)result between the surface (90) and the presser (7). Approximately atthe same time, the actuator (80) is started for cutting the reeling offweb (N1) and, thereafter, the presser (7) and actuator (80) are broughtback in their initial conditions (as shown in FIG. 6). In this way, theflow of webs toward the tube-forming machine (T) never stops. When theweb (N1′) is fully reeled off, the same operation will be performed onthe head of the successive stand-by web (N1) after attaching theadhesive tape (91) (and having provided, of course, for replacing thecorresponding reel in the meantime), as illustrated in the schematicdiagrams of FIGS. 8 and 9. In order to keep the web (N1) in stand-bycondition, it can be used the same reed above described (9) whichretains the head of web (N1) adherent to a fixed surface (99) located infront of the fixed surface (90).

A structure according to the invention allows also using, for eachmodule, that is, for each of the webs fed to the tube-forming machine(T), a device for controlling the tension of the webs. Such device,according to the example illustrated in FIG. 10, comprises a plate (100)mounted on two vertical guiding rails (101) and provided with tworollers (44) for the guide of a corresponding web in cooperation withthe other fixed rollers (4) of the system. The plate is engaged on topwith the rod of a pneumatic cylinder (110) having dual (lower/upper)chamber, so that the position of the plate (100) corresponds to that ofthe rod of cylinder (110). The lower chamber of the cylinder (110) issupplied with compressed air via a controller (300) which allowsadjusting the resistance to the lowering of the plate (100) engaged withthe rod of cylinder (110). The upper chamber of the latter ispneumatically connected to two pneumatic grippers (400) each of whichacts on a corresponding disc (401) keyed on the axis (2) of reels (3,3′) of the structure's module associated with the device.

During operation, the diameter of the reel (3, 3′) becomes smaller andsmaller and, since the tension applied on the respective web (N1) isconstant and corresponds to the return action operated by thetube-forming machine (T), the plate (100) tends to come down by drivingalong with it the rod of cylinder (110) and, thereby, increasing thevolume of the upper chamber of the latter. This brings about a reductionof the pressure exerted on the grippers (400) and, accordingly, agradual reduction of the braking action applied on the discs (401) ofaxis (2). In this way, practically, the tension of the web is keptconstant in the portion between the respective reel and the tube-formingmachine also when the diameter of the reel becomes smaller and smaller.

Practically, (all) the construction details may vary in any equivalentway as far as the shape, dimensions, elements disposition, nature of theused materials are concerned, without nevertheless departing from thescope of the adopted solution idea and, thereby, remaining within thelimits of the protection granted to the present patent for industrialinvention.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. Apparatus for feeding paper webs and the like, for producingcardboard tubes, the apparatus comprising: a plan modular structure witha development mostly longitudinal and exhibiting two opposite surfaces,one of said surfaces supporting pairs of shafts or axes horizontallyoriented parallel to said one surface and located at a preset distancefrom the ground, each of said shafts or axes intended to support atleast a reel from which a paper web unwinds, so that the output webs runparallel and superimposed to each other along the other surface of thestructure, and in that it comprises automatic means, associated withsaid structure, for the cutting and mutual gluing of the webs whichunwind from two different reels of a same pair of shafts.
 2. Apparatusaccording to claim 1, wherein said structure has a plurality of slits orwindows through which said webs can pass from the side of a surface tothe side of the other surface.
 3. Apparatus according to claim 1,further comprising means associated with said structure for guiding saidwebs.
 4. Apparatus according to claim 1, further comprising meansassociated with said structure for the ventral gluing of a portion ofsaid webs.
 5. Apparatus according to claim 1, further comprising meansfor adjusting the tension of the webs which run along said surfaceopposite to the surface that supports said shafts.